I've caught the folding bug and I'm considering a six speed Brompton and a Tern Link P9. Obviously the Brompton folds smaller, but I look at the gearing set up and only it could have been designed in England (I'm English so I can say that). Is that a plastic derailleur? I like the Tern because it uses pretty standard modern bike components and I can see myself customizing it easily.

So what are your opinions about the Brompton parts, they seem pretty old fashioned and has anyone had issues with that flimsy looking derailleur system?